title: Monosodium glutamate (MSG) consumption is associated with urolithiasis and urinary tract obstruction in rats.
abstract: BACKGROUND
  The peritoneal injection of monosodium glutamate (MSG) can induce kidney injury in adult rats but the effects of long-term oral intake have not been determined.
  
  
  METHODS
  We investigated the kidney histology and function in adult male Wistar rats that were fed ad libitum with a standard rat chow pellet and water with or without the addition of 2 mg/g body weight MSG/day in drinking water (n=10 per group). Both MSG-treated and control animals were sacrificed after 9 months when renal function parameters, blood and urine electrolytes, and tissue histopathology were determined.
  
  
  RESULTS
  MSG-treated rats were more prone to kidney stone formation, as represented by the alkaline urine and significantly higher activity product of calcium phosphate. Accordingly, 3/10 MSG-treated rats developed kidney stones over 9 months versus none of the control animals. Further, 2/10 MSG-treated rats but none (0/10) of the controls manifested hydronephrosis. MSG-treated rats had significantly higher levels of serum creatinine and potassium including urine output volume, urinary excretion sodium and citrate compared to controls. In contrast, MSG-treated rats had significantly lower ammonium and magnesium urinary excretion.
  
  
  CONCLUSIONS
  Oral MSG consumption appears to cause alkaline urine and may increase the risks of kidney stones with hydronephrosis in rats. Similar effects in humans must be verified by dedicated studies.
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
authors.forename: Amod
authors.initials: A
authors.lastname: Sharma
authors.forename: Vitoon
authors.initials: V
authors.lastname: Prasongwattana
authors.forename: Ubon
authors.initials: U
authors.lastname: Cha'on
authors.forename: Carlo
authors.initials: C
authors.lastname: Selmi
authors.forename: Wiphawi
authors.initials: W
authors.lastname: Hipkaeo
authors.forename: Piyanard
authors.initials: P
authors.lastname: Boonnate
authors.forename: Supattra
authors.initials: S
authors.lastname: Pethlert
authors.forename: Tanin
authors.initials: T
authors.lastname: Titipungul
authors.forename: Piyapharom
authors.initials: P
authors.lastname: Intarawichian
authors.forename: Sakda
authors.initials: S
authors.lastname: Waraasawapati
authors.forename: Anucha
authors.initials: A
authors.lastname: Puapiroj
authors.forename: Visith
authors.initials: V
authors.lastname: Sitprija
authors.forename: Sirirat
authors.initials: S
authors.lastname: Reungjui
mesh_terms: D000818:Animals; D004435:Eating / Q000502:physiology; D004573:Electrolytes / Q000097:blood / Q000652:urine; D007668:Kidney / Q000473:pathology; D007669:Kidney Calculi / Q000097:blood / Q000209:etiology / Q000473:pathology / Q000652:urine; D007677:Kidney Function Tests / Q000379:methods; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012964:Sodium / Q000378:metabolism; D012970:Sodium Glutamate / Q000009:adverse effects*; D052878:Urolithiasis / Q000097:blood / Q000209:etiology* / Q000473:pathology / Q000652:urine; D014570:Urologic Diseases / Q000097:blood / Q000209:etiology* / Q000473:pathology / Q000652:urine; D014867:Water / Q000378:metabolism
chemical_list: D004573:Electrolytes; D014867:Water; D012964:Sodium; D012970:Sodium Glutamate